1. Field of the Invention
The present invention relates to a software development tool and more particularly, to a software development supporting system of the Read-Only memory (ROM) emulation type and a ROM emulation apparatus that are designed for a microprocessor-based target system having a Peripheral Component Interconnector (PCI) bus, in which a target ROM is controlled by a ROM controller through the PCI bus under the control of a microprocessor.
2. Description of the Prior Art
A conventional software development supporting system of this sort is disclosed in the Japanese Non-Examined Patent Publication No. 64-9542 published in January 1989.
This conventional system includes a ROM emulator designed to be electrically connected to a host computer. This ROM emulator is equipped with a user Random-Access Memory (RAM) for storing a user program, a trace RAM for storing a trace program, and a controller for controlling the user and trace programs and the emulation procedure. Further, this ROM emulator has a probe for electrically connecting this ROM emulator to a user system or target system on which a Central Processing Unit (CPU) and a target ROM are mounted. The probe of the ROM emulator is designed to be electrically coupled with the target ROM.
When a user program is produced or developed in the host computer, this user program is transmitted to the user RAM mounted on the ROM emulator and stored therein. Then, the user program in the user RAM is traced on the ROM emulator using the trace program stored in the trace RAM under the control of the CPU and the controller. The ROM emulator emulates the operation of the target ROM (i.e., the program stored in the target ROM) mounted on the user system.
In the above-described conventional software development supporting system disclosed in the Japanese Non-Examined Patent Publication No. 64-9542, there is a following problem.
Specifically, to electrically connect the ROM emulator to the user system or target system, the probe of the ROM emulator needs to be coupled with a ROM socket fixed on the target system for mounting the target ROM. This means that a ROM socket is necessarily mounted on the target system for electrical coupling of the ROM emulator. Therefore, this conventional software development supporting system is unable or very difficult to be electrically connected to a user or target system in which a target ROM is directly fixed onto a system board with solder and no ROM socket is equipped for the target ROM.
For example, to electrically connect this conventional software development supporting system to the user or target system, a ROM socket needs to be temporarily mounted on the system board after the target ROM isolated onto the system board is removed therefrom.
A dedicated ROM socket for the ROM emulator may be provided on the user system in advance. In this case, however, this dedicated ROM socket will causes a disadvantage that the size and cost of the system board is increased.